Mega Man Legends 3 is the planned sequel to Mega Man Legends 2, which would have been the fourth game in the Mega Man Legends series. It was announced for the Nintendo 3DS on September 29, 2010.[3]

During the game's development, Capcom created a development room website in Japan and North America known as the Devroom. In the Devroom, fans could watch the game's development and participate in events and contests that allowed them to contribute to Mega Man Legends 3 by voting on character designs and the like.

On July 18, 2011, Capcom announced the cancellation of Mega Man Legends 3, stating that "it was not felt that the Mega Man Legends 3 Project met the required criteria",[4] but did not give any further explanation.

Mega Man Legends 3: Prototype Version is an early version of the game that would have been available for download on the Nintendo eShop. It was originally going to be available upon the launch of the eShop,[5] but was delayed.

Initially, Capcom stated that Mega Man Legends 3 would be cancelled if the Prototype Version didn't sell well,[6] but the Prototype Version was cancelled along with the full game.